Preheat oven to 375 degrees F.
Rub oil over bell peppers; place on baking sheet face down. Roast until tender, approximately 20 minutes.
In a large mixing bowl, combine couscous, wild rice, sauteed mushrooms, parsley, cranberry raisins, salt, pepper, and vinaigrette. Toss to combine.
Fill each pepper half with couscous mixture and serve.